elogtool: Fix potential buffer overrun

BUG=b:239110778
TEST=Make sure that the output of elogtool is unaffected by this change.

Signed-off-by: Kapil Porwal <kapilporwal@google.com>
Change-Id: Ia1a6341abd834dd9ad5f12c9f2eefb0489364a08
Reviewed-on: https://review.coreboot.org/c/coreboot/+/72099
Reviewed-by: Subrata Banik <subratabanik@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
This commit is contained in:
Kapil Porwal 2023-01-20 01:00:42 +05:30 committed by Felix Held
parent 79312afdde
commit 0b6954b8d5
2 changed files with 38 additions and 3 deletions

View File

@ -196,7 +196,11 @@ static int cmd_list(const struct buffer *buf)
event = buffer_get(buf) + sizeof(struct elog_header); event = buffer_get(buf) + sizeof(struct elog_header);
while ((const void *)(event) < buffer_end(buf)) { while ((const void *)(event) < buffer_end(buf)) {
if (event->type == ELOG_TYPE_EOL || event->length == 0) if (((const void *)event + sizeof(*event)) >= buffer_end(buf)
|| event->length <= sizeof(*event)
|| event->length > ELOG_MAX_EVENT_SIZE
|| ((const void *)event + event->length) >= buffer_end(buf)
|| event->type == ELOG_TYPE_EOL)
break; break;
eventlog_print_event(event, count); eventlog_print_event(event, count);

View File

@ -460,6 +460,32 @@ static int eventlog_print_data(const struct event_header *event)
{0, NULL}, {0, NULL},
}; };
size_t elog_type_to_min_size[] = {
[ELOG_TYPE_LOG_CLEAR] = sizeof(uint16_t),
[ELOG_TYPE_BOOT] = sizeof(uint32_t),
[ELOG_TYPE_LAST_POST_CODE] = sizeof(uint16_t),
[ELOG_TYPE_POST_EXTRA] = sizeof(uint32_t),
[ELOG_TYPE_OS_EVENT] = sizeof(uint32_t),
[ELOG_TYPE_ACPI_ENTER] = sizeof(uint8_t),
[ELOG_TYPE_ACPI_WAKE] = sizeof(uint8_t),
[ELOG_TYPE_ACPI_DEEP_WAKE] = sizeof(uint8_t),
[ELOG_TYPE_WAKE_SOURCE] = sizeof(struct elog_event_data_wake),
[ELOG_TYPE_EC_EVENT] = sizeof(uint8_t),
[ELOG_TYPE_EC_DEVICE_EVENT] = sizeof(uint8_t),
[ELOG_DEPRECATED_TYPE_CROS_RECOVERY_MODE] = sizeof(uint8_t),
[ELOG_TYPE_MANAGEMENT_ENGINE] = sizeof(uint8_t),
[ELOG_TYPE_MEM_CACHE_UPDATE] = sizeof(struct elog_event_mem_cache_update),
[ELOG_TYPE_EXTENDED_EVENT] = sizeof(struct elog_event_extended_event),
[ELOG_TYPE_CROS_DIAGNOSTICS] = sizeof(uint8_t),
[ELOG_TYPE_FW_VBOOT_INFO] = sizeof(uint16_t),
[0xff] = 0,
};
if (event->length <= sizeof(*event) + elog_type_to_min_size[event->type]) {
eventlog_printf("INVALID DATA (length = %u)", event->length - sizeof(*event));
return 0;
}
switch (event->type) { switch (event->type) {
case ELOG_TYPE_LOG_CLEAR: { case ELOG_TYPE_LOG_CLEAR: {
const uint16_t *bytes = event_get_data(event); const uint16_t *bytes = event_get_data(event);
@ -587,10 +613,15 @@ static int eventlog_print_data(const struct event_header *event)
eventlog_printf("boot_mode=%s", vb2_boot_mode_string(info->boot_mode)); eventlog_printf("boot_mode=%s", vb2_boot_mode_string(info->boot_mode));
if (info->boot_mode == VB2_BOOT_MODE_BROKEN_SCREEN || if (info->boot_mode == VB2_BOOT_MODE_BROKEN_SCREEN ||
info->boot_mode == VB2_BOOT_MODE_MANUAL_RECOVERY) info->boot_mode == VB2_BOOT_MODE_MANUAL_RECOVERY) {
if (event->length <= sizeof(*event) + sizeof(*info))
eventlog_printf("INVALID DATA (length = %u)",
event->length - sizeof(*event));
else
eventlog_printf("recovery_reason=%#x/%#x (%s)", eventlog_printf("recovery_reason=%#x/%#x (%s)",
info->recovery_reason, info->recovery_subcode, info->recovery_reason, info->recovery_subcode,
vb2_get_recovery_reason_string(info->recovery_reason)); vb2_get_recovery_reason_string(info->recovery_reason));
}
eventlog_printf("fw_tried=%s", vb2_slot_string(info->slot)); eventlog_printf("fw_tried=%s", vb2_slot_string(info->slot));
eventlog_printf("fw_try_count=%d", info->tries); eventlog_printf("fw_try_count=%d", info->tries);